Synthetic and biological studies on a cyclopolypeptide of plant origin

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.     

In vitro assessment of gastrointestinal viability of two photosynthetic bacteria, <Emphasis Type="Italic">Rhodopseudomonas palustris</Emphasis> and <Emphasis Type="Italic">Rhodobacter sphaeroides</Emphasis>

The objectives of this study were to assess the potential of two photosynthetic bacteria （PSB）, Rhodopseudomonas palustris HZ0301 and Rhodobacter sphaeroides HZ0302, as probiotics in aquaculture. The viability of HZ0301 and HZ0302 in simulated gastric transit conditions （pH 2.0, pH 3.0 and pH 4.0 gastric juices） and in simulated small intestinal transit conditions （pH 8.0, with or without 0.3% bile salts） was tested. The effects of HZ0301 and HZ0302 on the viability and permeability of intestinal epithelial cell in primary culture of tilapias, Oreochrornis nilotica, were also detected. All the treatments were deter- mined with three replicates. The simulated gastric transit tolerance of HZ0301 and HZ0302 strains was pH-dependent and correspondingly showed lower viability at pH 2.0 after 180 min compared with pH 3.0 and pH 4.0. Both HZ0301 and HZ0302 were tolerant to simulated small intestine transit with or without bile salts in our research. Moreover, there was no significant difference （P〉0.05） among three treatments including the control and the groups treated with HZ0301 or HZ0302 both in intestinal epithelial cell viability and membrane permeability, showing no cell damage. In summary, this study demonstrated that HZ0301 and HZ0302 had high capacity of upper gastrointestinal transit tolerance and were relatively safe for intestinal epithelial cells of tilapias.     

A probiotic treatment containing Lactobacillus, Bifidobacterium and Enterococcus improves IBS symptoms in an open label trial

INTRODUCTION Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder. The typical symptoms are abdominal pain, flatulence, and irregular bowel movement. Prevalence rates are re- ported to be as high as 30% in the general population (Drossman et al., 1982), corresponding to about 25%~50% of all patients who need gastroenterolo- gist’s help (Everhart and Renault, 1991). Despite this high prevalence, the cause of IBS is unknown. Many factors are likely to …     

五磨脐贴促进腹部手术患者胃肠功能的恢复及对血清血管活性肠肽和降钙素基因相关肽的影响

目的通过观察腹部手术治疗后患者肠麻痹恢复情况,评价五磨脐贴对腹部术后胃肠功能恢复的促进作用;观察腹部手术患者血清中血管活性肠肽和降钙素基因相关肽的变化及五磨脐贴对其影响,探讨五磨脐贴促进腹部手术患者胃肠功能恢复的机理。方法80例患者分为两组,治疗组采用五磨脐贴外敷神阙穴,对照组不使用任何促胃肠动力药,观察患者术后肠鸣音恢复时间及术后肛门排气时间,观察两组血管活性肠肽和降钙素基因相关肽的变化。结果术后肠鸣音恢复时间及术后肛门排气时间组间比较,五磨脐贴治疗组的时间明显短于空白对照组,差异有显著性意义(P<0.01)。治疗前,两组血管活性肠肽和降钙素基因相关肽含量无=明显差异(P>0.05);治疗后,治疗组血管活性肠肽和降钙素基因相关肽较对照组明显降低,差异有显著意义P<0.05);五磨脐贴治疗组治疗前血管活性肠肽和降钙素基因相关肽含量明显高于治疗后,差异有非常显著性意义(P<0.01)。结论五磨脐贴抑制腹部手术患者血管活性肠肽和降钙素基因相关肽的分泌,促进胃肠功能的恢复。     

补充大豆多肽对递增负荷运动大鼠血清LDH、ALT、AST活性的影响

观察了5周递增负荷训练并同时补充大豆多肽后的大鼠在运动后某些血清酶的变化,旨为在训练中补充大豆多肽对身体机能及运动后恢复的作用提供一定的理论依据.结果发现:补充大豆多肽降低了运动后血清LDH和AST活性.提示:补充大豆多肽可能起到预防骨骼肌和心肌运动性微损伤和促进损伤恢复的作用.     

Carbohydrate gel ingestion during running in the heat on markers of gastrointestinal distress

The purpose of this study is to measure the effects of carbohydrate ingestion during exercise in the heat by measuring markers of gastrointestinal damage and inflammation. Methods: Active subjects (n?=?7) completed two 60-min running trials in a heated environment (70% VO₂max, 30°C). At minute 20 of exercise, subjects consumed a carbohydrate gel (Cho) (27?g), or a non-carbohydrate placebo (nCho). Plasma endotoxin, I-FABP, TNF-α, IL-6, IL-1β, IL-10, and MCP-1 were measured pre-exercise, 20-min post-exercise, and again 2-h, and 4-h post-exercise. Results: Endotoxin increased 20-min post-exercise compared to pre in the Cho trial only (p?=?.03). I-FABP levels increased 20-min post-exercise in the Cho trial only compared to pre-exercise (p?=?.003). I-FABP levels were also increased in Cho trial 20-min post-exercise when compared to same time point in the nCho trial (p?=?.032). TNF-α increased 20-min post-exercise in the Cho trial only compared to pre (p?=?.03). Plasma IL-6 concentration increased 20-min post-exercise when compared to pre in both the Cho (p?=?.002) and nCho (p?=?.009), but remained elevated at the 2-h time point in the nCho trial (p?=?.03). I-FABP and several plasma cytokines (TNF-α, MCP-1, Il-6) returned to baseline sooner in the Cho trial. Conclusions: Ingestion of carbohydrate gel during exercise in the heat enhances markers of gastrointestinal wall damage.     

Mechanism of acute pancreatitis complicated with injury of intestinal mucosa barrier

Acute pancreatitis （AP） is a common acute abdomen in clinic with a rapid onset and dangerous pathogenetic condition AP can cause an injury of intestinal mucosa barrier, leading to translocation of bacteria or endotoxin through multiple routes, bacterial translocation （BT）, gutorigin endotoxaemia, and secondary infection of pancreatic tissue, and then cause systemic inflammatory response syndrome （SIRS） or multiple organ dysfunction syndrome （MODS）, which are important factors influencing AP＇s severity and mortality. Meanwhile, the injury of intestinal mucosa barrier plays a key role in AP＇s process. Therefore, it is clinically important to study the relationship between the injury of intestinal mucosa barrier and AP. In addition, many factors such as microcirculation disturbance, ischemical reperfusion injury, excessive release of inflammatory mediators and apoptosis may also play important roles in the damage of intestinal mucosa barrier. In this review, we summarize studies on mechanisms of AP.     

Molecular dynamics simulation of the interactions between EHD1 EH domain and multiple peptides

Objective: To provide essential information for peptide inhibitor design, the interactions of Eps15 homology domain of Eps15 homology domain-containing protein 1 (EHD1 EH domain) with three peptides containing NPF (asparagine-proline-phenylalanine), DPF (aspartic acid-proline-phenylalanine), and GPF (glycine-proline-phenylalanine) motifs were deciphered at the atomic level. The binding affinities and the underlying structure basis were investigated. Methods: Molecular dynamics (MD) simulations were performed on EHD1 EH domain/peptide complexes for 60 ns using the GROMACS package. The binding free energies were calculated and decomposed by molecular mechanics/generalized Born surface area (MM/GBSA) method using the AMBER package. The alanine scanning was performed to evaluate the binding hot spot residues using FoldX software. Results: The different binding affinities for the three peptides were affected dominantly by van der Waals interactions. Intermolecular hydrogen bonds provide the structural basis of contributions of van der Waals interactions of the flanking residues to the binding. Conclusions: van der Waals interactions should be the main consideration when we design peptide inhibitors of EHD1 EH domain with high affinities. The ability to form intermolecular hydrogen bonds with protein residues can be used as the factor for choosing the flanking residues.     

An intelligent electronic capsule system for automated detection of gastrointestinal bleeding

In clinical practice, examination of the hemorrhagic spot (HS) remains difficult. In this paper, we describe a remote controlled capsule (RCC) micro-system with an automated, color-based sensor to identify and localize the HS of the gastrointestinal (GI) tract. In vitro testing of the detecting sensor demonstrated that it was capable of discriminating mimetic intestinal fluid (MIF) with and without the hemoglobin (Hb) when the concentration of Hb in MIF was above 0.05 g/ml. Therefore, this RCC system is able to detect the relatively accurate location of the HS in the GI tract.     

运动对心脑血管系统内皮素及降钙素基因相关肽的影响

运动对心脑血管生长的影响在临床中已获得资料。本文回顾了对血管的收缩和舒张有重要作用的内皮素和降钙素基因相关肽分子生物学方面的研究，认为两者的生物学活性对运动心脏的形成和心脏康复有重要的调节作用，，深入对它们的研究将使我们从分子生物学水平加深运动心脏与运动疗法和心脏康复在机理方面的认识。